[PATCH v2 0/3] Add dw_mmc support for rk3576

[PATCH v2 0/3] Add dw_mmc support for rk3576

[Detlev Casanova]

The SD card controller on the rk3576 SoC uses a new tuning version that is
capable of using pre-boot tuning information.

Also, it stores the phase settings into the dw_mmc controller, so the code
has to be adapted to implement that.

Changes since v1:
- Renamed use-v2-tuning to v2-tuning
- Rewrite v2-tuning description as the hardware feature

Detlev Casanova (1):
  dt-bindings: mmc: Add support for rk3576 dw-mshc

Shawn Lin (2):
  mmc: dw_mmc-rockchip: Add v2 tuning support
  mmc: dw_mmc-rockchip: Add internal phase support

 .../bindings/mmc/rockchip-dw-mshc.yaml        |   7 +
 drivers/mmc/host/dw_mmc-rockchip.c            | 223 +++++++++++++++++-
 2 files changed, 221 insertions(+), 9 deletions(-)

-- 
2.46.0

[PATCH v2 1/3] dt-bindings: mmc: Add support for rk3576 dw-mshc

[Detlev Casanova]

Add the compatible string for rockchip,rk3576-dw-mshc and add support
for the rockchip,v2-tuning flag, a new feature of this core.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 .../devicetree/bindings/mmc/rockchip-dw-mshc.yaml          | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
index 211cd0b0bc5f3..86c986a7adb23 100644
--- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
+++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
@@ -39,6 +39,7 @@ properties:
               - rockchip,rk3368-dw-mshc
               - rockchip,rk3399-dw-mshc
               - rockchip,rk3568-dw-mshc
+              - rockchip,rk3576-dw-mshc
               - rockchip,rk3588-dw-mshc
               - rockchip,rv1108-dw-mshc
               - rockchip,rv1126-dw-mshc
@@ -95,6 +96,12 @@ properties:
       If not specified, the host will do tuning for 360 times,
       namely tuning for each degree.
 
+  rockchip,v2-tuning:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Specify when the v2 tuning is supported. In this case, the hardware
+      inherits pre-stage loader's phase settings.
+
 required:
   - compatible
   - reg
-- 
2.46.0

[PATCH v2 2/3] mmc: dw_mmc-rockchip: Add v2 tuning support

[Detlev Casanova]

From: Shawn Lin <shawn.lin@rock-chips.com>

v2 tuning will inherit pre-stage loader's phase settings for the first
time, and do re-tune if necessary.
Re-tune will still try the rough degrees, for instance, 90, 180, 270,
360 but continue to do the fine tuning if sample window isn't good
enough.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 drivers/mmc/host/dw_mmc-rockchip.c | 47 ++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index b07190ba4b7ac..b1b437ea878ae 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -24,6 +24,8 @@ struct dw_mci_rockchip_priv_data {
 	struct clk		*sample_clk;
 	int			default_sample_phase;
 	int			num_phases;
+	bool			use_v2_tuning;
+	int			last_degree;
 };
 
 static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
@@ -134,6 +136,42 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 #define TUNING_ITERATION_TO_PHASE(i, num_phases) \
 		(DIV_ROUND_UP((i) * 360, num_phases))
 
+static int dw_mci_v2_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
+{
+	struct dw_mci *host = slot->host;
+	struct dw_mci_rockchip_priv_data *priv = host->priv;
+	struct mmc_host *mmc = slot->mmc;
+	u32 degrees[4] = {90, 180, 270, 360};
+	int i;
+	static bool inherit = true;
+
+	if (inherit) {
+		inherit = false;
+		i = clk_get_phase(priv->sample_clk) / 90 - 1;
+		goto done;
+	}
+
+	/* v2 only support 4 degrees in theory */
+	for (i = 0; i < ARRAY_SIZE(degrees); i++) {
+		if (degrees[i] == priv->last_degree)
+			continue;
+
+		clk_set_phase(priv->sample_clk, degrees[i]);
+		if (!mmc_send_tuning(mmc, opcode, NULL))
+			break;
+	}
+
+	if (i == ARRAY_SIZE(degrees)) {
+		dev_warn(host->dev, "All phases bad!");
+		return -EIO;
+	}
+
+done:
+	dev_info(host->dev, "Successfully tuned phase to %d\n", degrees[i]);
+	priv->last_degree = degrees[i];
+	return 0;
+}
+
 static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 {
 	struct dw_mci *host = slot->host;
@@ -157,6 +195,13 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 		return -EIO;
 	}
 
+	if (priv->use_v2_tuning) {
+		ret = dw_mci_v2_execute_tuning(slot, opcode);
+		if (!ret)
+			return 0;
+		/* Otherwise we continue using fine tuning */
+	}
+
 	ranges = kmalloc_array(priv->num_phases / 2 + 1,
 			       sizeof(*ranges), GFP_KERNEL);
 	if (!ranges)
@@ -277,6 +322,8 @@ static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
 					&priv->default_sample_phase))
 		priv->default_sample_phase = 0;
 
+	priv->use_v2_tuning = of_property_read_bool(np, "rockchip,v2-tuning");
+
 	priv->drv_clk = devm_clk_get(host->dev, "ciu-drive");
 	if (IS_ERR(priv->drv_clk))
 		dev_dbg(host->dev, "ciu-drive not available\n");
-- 
2.46.0

[PATCH v2 3/3] mmc: dw_mmc-rockchip: Add internal phase support

[Detlev Casanova]

From: Shawn Lin <shawn.lin@rock-chips.com>

Some Rockchip devices put the phase settings into the dw_mmc controller.

The feature is implemented in devices where the USRID register contains
0x20230002.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 drivers/mmc/host/dw_mmc-rockchip.c | 180 +++++++++++++++++++++++++++--
 1 file changed, 169 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index b1b437ea878ae..4652691eb19f9 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -16,6 +16,17 @@
 #include "dw_mmc-pltfm.h"
 
 #define RK3288_CLKGEN_DIV	2
+#define USRID_INTER_PHASE	0x20230001
+#define SDMMC_TIMING_CON0	0x130
+#define SDMMC_TIMING_CON1	0x134
+#define ROCKCHIP_MMC_DELAY_SEL BIT(10)
+#define ROCKCHIP_MMC_DEGREE_MASK 0x3
+#define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
+#define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
+#define PSECS_PER_SEC 1000000000000LL
+#define ROCKCHIP_MMC_DELAY_ELEMENT_PSEC 60
+#define HIWORD_UPDATE(val, mask, shift) \
+		((val) << (shift) | (mask) << ((shift) + 16))
 
 static const unsigned int freqs[] = { 100000, 200000, 300000, 400000 };
 
@@ -25,9 +36,121 @@ struct dw_mci_rockchip_priv_data {
 	int			default_sample_phase;
 	int			num_phases;
 	bool			use_v2_tuning;
+	int			usrid;
 	int			last_degree;
 };
 
+/*
+ * Each fine delay is between 44ps-77ps. Assume each fine delay is 60ps to
+ * simplify calculations. So 45degs could be anywhere between 33deg and 57.8deg.
+ */
+static int rockchip_mmc_get_phase(struct dw_mci *host, bool sample)
+{
+	unsigned long rate = clk_get_rate(host->ciu_clk);
+	u32 raw_value;
+	u16 degrees;
+	u32 delay_num = 0;
+
+	/* Constant signal, no measurable phase shift */
+	if (!rate)
+		return 0;
+
+	if (sample)
+		raw_value = mci_readl(host, TIMING_CON1) >> 1;
+	else
+		raw_value = mci_readl(host, TIMING_CON0) >> 1;
+
+	degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90;
+
+	if (raw_value & ROCKCHIP_MMC_DELAY_SEL) {
+		/* degrees/delaynum * 1000000 */
+		unsigned long factor = (ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10) *
+					36 * (rate / 10000);
+
+		delay_num = (raw_value & ROCKCHIP_MMC_DELAYNUM_MASK);
+		delay_num >>= ROCKCHIP_MMC_DELAYNUM_OFFSET;
+		degrees += DIV_ROUND_CLOSEST(delay_num * factor, 1000000);
+	}
+
+	return degrees % 360;
+}
+
+static int rockchip_mmc_set_phase(struct dw_mci *host, bool sample, int degrees)
+{
+	unsigned long rate = clk_get_rate(host->ciu_clk);
+	u8 nineties, remainder;
+	u8 delay_num;
+	u32 raw_value;
+	u32 delay;
+
+	/*
+	 * The below calculation is based on the output clock from
+	 * MMC host to the card, which expects the phase clock inherits
+	 * the clock rate from its parent, namely the output clock
+	 * provider of MMC host. However, things may go wrong if
+	 * (1) It is orphan.
+	 * (2) It is assigned to the wrong parent.
+	 *
+	 * This check help debug the case (1), which seems to be the
+	 * most likely problem we often face and which makes it difficult
+	 * for people to debug unstable mmc tuning results.
+	 */
+	if (!rate) {
+		dev_err(host->dev, "%s: invalid clk rate\n", __func__);
+		return -EINVAL;
+	}
+
+	nineties = degrees / 90;
+	remainder = (degrees % 90);
+
+	/*
+	 * Due to the inexact nature of the "fine" delay, we might
+	 * actually go non-monotonic.  We don't go _too_ monotonic
+	 * though, so we should be OK.  Here are options of how we may
+	 * work:
+	 *
+	 * Ideally we end up with:
+	 *   1.0, 2.0, ..., 69.0, 70.0, ...,  89.0, 90.0
+	 *
+	 * On one extreme (if delay is actually 44ps):
+	 *   .73, 1.5, ..., 50.6, 51.3, ...,  65.3, 90.0
+	 * The other (if delay is actually 77ps):
+	 *   1.3, 2.6, ..., 88.6. 89.8, ..., 114.0, 90
+	 *
+	 * It's possible we might make a delay that is up to 25
+	 * degrees off from what we think we're making.  That's OK
+	 * though because we should be REALLY far from any bad range.
+	 */
+
+	/*
+	 * Convert to delay; do a little extra work to make sure we
+	 * don't overflow 32-bit / 64-bit numbers.
+	 */
+	delay = 10000000; /* PSECS_PER_SEC / 10000 / 10 */
+	delay *= remainder;
+	delay = DIV_ROUND_CLOSEST(delay,
+			(rate / 1000) * 36 *
+				(ROCKCHIP_MMC_DELAY_ELEMENT_PSEC / 10));
+
+	delay_num = (u8) min_t(u32, delay, 255);
+
+	raw_value = delay_num ? ROCKCHIP_MMC_DELAY_SEL : 0;
+	raw_value |= delay_num << ROCKCHIP_MMC_DELAYNUM_OFFSET;
+	raw_value |= nineties;
+
+	if (sample)
+		mci_writel(host, TIMING_CON1, HIWORD_UPDATE(raw_value, 0x07ff, 1));
+	else
+		mci_writel(host, TIMING_CON0, HIWORD_UPDATE(raw_value, 0x07ff, 1));
+
+	dev_dbg(host->dev, "set %s_phase(%d) delay_nums=%u actual_degrees=%d\n",
+		sample ? "sample" : "drv", degrees, delay_num,
+		rockchip_mmc_get_phase(host, sample)
+	);
+
+	return 0;
+}
+
 static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 {
 	struct dw_mci_rockchip_priv_data *priv = host->priv;
@@ -65,8 +188,12 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 	}
 
 	/* Make sure we use phases which we can enumerate with */
-	if (!IS_ERR(priv->sample_clk) && ios->timing <= MMC_TIMING_SD_HS)
-		clk_set_phase(priv->sample_clk, priv->default_sample_phase);
+	if (!IS_ERR(priv->sample_clk) && ios->timing <= MMC_TIMING_SD_HS) {
+		if (priv->usrid == USRID_INTER_PHASE)
+			rockchip_mmc_set_phase(host, true, priv->default_sample_phase);
+		else
+			clk_set_phase(priv->sample_clk, priv->default_sample_phase);
+	}
 
 	/*
 	 * Set the drive phase offset based on speed mode to achieve hold times.
@@ -129,7 +256,10 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 			break;
 		}
 
-		clk_set_phase(priv->drv_clk, phase);
+		if (priv->usrid == USRID_INTER_PHASE)
+			rockchip_mmc_set_phase(host, false, phase);
+		else
+			clk_set_phase(priv->drv_clk, phase);
 	}
 }
 
@@ -147,7 +277,10 @@ static int dw_mci_v2_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 
 	if (inherit) {
 		inherit = false;
-		i = clk_get_phase(priv->sample_clk) / 90 - 1;
+		if (priv->usrid == USRID_INTER_PHASE)
+			i = rockchip_mmc_get_phase(host, true) / 90;
+		else
+			i = clk_get_phase(priv->sample_clk) / 90 - 1;
 		goto done;
 	}
 
@@ -156,7 +289,12 @@ static int dw_mci_v2_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 		if (degrees[i] == priv->last_degree)
 			continue;
 
-		clk_set_phase(priv->sample_clk, degrees[i]);
+		u32 degree = degrees[i] + priv->last_degree + 90;
+		degree = degree % 360;
+		if (priv->usrid == USRID_INTER_PHASE)
+			rockchip_mmc_set_phase(host, true, degree);
+		else
+			clk_set_phase(priv->sample_clk, degree);
 		if (!mmc_send_tuning(mmc, opcode, NULL))
 			break;
 	}
@@ -209,8 +347,15 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 
 	/* Try each phase and extract good ranges */
 	for (i = 0; i < priv->num_phases; ) {
-		clk_set_phase(priv->sample_clk,
-			      TUNING_ITERATION_TO_PHASE(i, priv->num_phases));
+		/* Cannot guarantee any phases larger than 270 would work well */
+		if (TUNING_ITERATION_TO_PHASE(i, priv->num_phases) > 270)
+			break;
+		if (priv->usrid == USRID_INTER_PHASE)
+			rockchip_mmc_set_phase(host, true,
+				TUNING_ITERATION_TO_PHASE(i, priv->num_phases));
+		else
+			clk_set_phase(priv->sample_clk,
+				TUNING_ITERATION_TO_PHASE(i, priv->num_phases));
 
 		v = !mmc_send_tuning(mmc, opcode, NULL);
 
@@ -256,7 +401,10 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 	}
 
 	if (ranges[0].start == 0 && ranges[0].end == priv->num_phases - 1) {
-		clk_set_phase(priv->sample_clk, priv->default_sample_phase);
+		if (priv->usrid == USRID_INTER_PHASE)
+			rockchip_mmc_set_phase(host, true, priv->default_sample_phase);
+		else
+			clk_set_phase(priv->sample_clk, priv->default_sample_phase);
 		dev_info(host->dev, "All phases work, using default phase %d.",
 			 priv->default_sample_phase);
 		goto free;
@@ -296,9 +444,12 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 	dev_info(host->dev, "Successfully tuned phase to %d\n",
 		 TUNING_ITERATION_TO_PHASE(middle_phase, priv->num_phases));
 
-	clk_set_phase(priv->sample_clk,
-		      TUNING_ITERATION_TO_PHASE(middle_phase,
-						priv->num_phases));
+	if (priv->usrid == USRID_INTER_PHASE)
+		rockchip_mmc_set_phase(host, true, TUNING_ITERATION_TO_PHASE(middle_phase,
+                                                priv->num_phases));
+	else
+		clk_set_phase(priv->sample_clk, TUNING_ITERATION_TO_PHASE(middle_phase,
+                                                priv->num_phases));
 
 free:
 	kfree(ranges);
@@ -340,6 +491,7 @@ static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
 static int dw_mci_rockchip_init(struct dw_mci *host)
 {
 	int ret, i;
+	struct dw_mci_rockchip_priv_data *priv = host->priv;
 
 	/* It is slot 8 on Rockchip SoCs */
 	host->sdio_id0 = 8;
@@ -363,6 +515,12 @@ static int dw_mci_rockchip_init(struct dw_mci *host)
 			dev_warn(host->dev, "no valid minimum freq: %d\n", ret);
 	}
 
+	priv->usrid = mci_readl(host, USRID);
+	if (priv->usrid == USRID_INTER_PHASE) {
+		priv->sample_clk = NULL;
+		priv->drv_clk = NULL;
+	}
+
 	return 0;
 }
 
-- 
2.46.0

Re: [PATCH v2 1/3] dt-bindings: mmc: Add support for rk3576 dw-mshc

[Krzysztof Kozlowski]

On 08/08/2024 18:47, Detlev Casanova wrote:
> Add the compatible string for rockchip,rk3576-dw-mshc and add support
> for the rockchip,v2-tuning flag, a new feature of this core.
> 
> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
> ---
>  .../devicetree/bindings/mmc/rockchip-dw-mshc.yaml          | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
> index 211cd0b0bc5f3..86c986a7adb23 100644
> --- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
> +++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
> @@ -39,6 +39,7 @@ properties:
>                - rockchip,rk3368-dw-mshc
>                - rockchip,rk3399-dw-mshc
>                - rockchip,rk3568-dw-mshc
> +              - rockchip,rk3576-dw-mshc
>                - rockchip,rk3588-dw-mshc
>                - rockchip,rv1108-dw-mshc
>                - rockchip,rv1126-dw-mshc
> @@ -95,6 +96,12 @@ properties:
>        If not specified, the host will do tuning for 360 times,
>        namely tuning for each degree.
>  
> +  rockchip,v2-tuning:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description:
> +      Specify when the v2 tuning is supported. In this case, the hardware
> +      inherits pre-stage loader's phase settings.

Is supported? This sounds compatible specific, so drop it. Unless it is
bootloader dependent, but how?

Best regards,
Krzysztof